then the fireworks. >> my father-in-law was in the navy, he passed away. i'm trying to honor him. >> reporter: a slew of stars will take the concert stage from megan hilde of "smash" to "american idol" winner phillip phillips and math through broderick. this family will be spending their evening somewhere on the mall. >> not sure, depends on how crowded it is. >> reporter: getting around downtown tonight could be tough. between a lack of parking and multiple street closures, public transportation may be the way to go. something else to try? a new communication system put out by u.s. park police, it can send weather advisories, security information, even information on a missing child to your phone. >> the public would sign up for this. it's as simple as texting july4s july4sdc to 888777 and you will receive all the july 4 event notifications. >> reporter: hundreds of thousands are expected here, millions are expected to watch from home and troops around the world will be listening. >> i know it's bitter sweet for them to hear the music, see the sights and